Data visualization is an important concept that is used to assist audiences in understanding complex ideas easily, identifying patterns and trends quickly, and making the most of the presented data. With the current proliferation of data generation, finding ways of extracting, cleaning, and visualizing data to enable easier interpretation is increasingly on demand.

Furthermore, if data visualization is accompanied with interactive capabilities, the audience can drill down to the finer details of the charts, graphs, maps, and dashboards and retrieve useful analysis and insights.

In the world of JavaScript programming, there are several charting libraries that allow developers to create stunning charts and visualize data without much hassle. Whether you require an open sourced library, paid-for library, or any other type, you can find something to take your data visualization efforts to the next level.

Some of the best JavaScript charting libraries include Google Charts, AnyChart, D3, and Highcharts. Basically, the process of creating interactive charts with any of them tends to be quite similar. So, once you’ve mastered how to use one, you can easily extrapolate the process to the other libraries, especially if you need a unique feature present in any of them.

For this JS chart tutorial, we’ll use examples from AnyChart. It’s a flexible and easy to use HTML5 JavaScript charting library that comes with exhaustive documentation, an extensive variety of supported chart types, code playground to test out things, and lots of other interesting features.

How to Create a Simple JS Bar Chart in 3 Steps

Here are three simple steps you can use to create a basic chart in JavaScript and integrate it into your website or application.

Prepare the data.

Connect to a JS charts library.

Write some code.

Now, let’s talk about each of the steps.

1. Preparing the Data

If you have unstructured data, you need to prepare it for easier loading into the charting library. Depending on the library you choose, you’ll need to prepare the data in the format it accepts. In the case of AnyChart, it supports a wide range of data formats, including Google Spreadsheet, XML, CSV, HTML, and JSON.

When creating most charts, you just need to provide the values for the X and Y axes. Creating bar charts is even simpler because you only need to provide values for the Y-axis, and an index number or an item number will be taken to represent the X-axis values.

For example, if we prepare the data in an array format, X will be the item numbers and Y will be the data values.

2. Connecting to a Charting Library

To connect to your preferred JavaScript charting library, you can choose to download the relevant package and store it locally or use a CDN service. A CDN is usually recommended because it allows you to load the library’s files from the server closest to your audience, which provides quick page load speeds and enhanced performance.

AnyChart uses a modular-based system that enables you to connect only the chart types and features you need in your project, considerably shrinking the size of the code running on our application.

For example, if we want to create a bar chart using AnyChart JS, we’ll need to add the following Core and basic Cartesian modules:

As you can see, using the AnyChart library for creating beautiful charts is easy and straightforward.

Now, let’s talk about how to enhance the look and feel of the charts using some more advanced steps.

How to Create Advanced JavaScript Bar Charts

Since we already know how to create a bar chart using AnyChart, let's see what else is possible in case we have a bit more sophisticated data visualization tasks to perform. You’ll see that JavaScript charting is not a rocket science for web developers.

For example, here are some advanced out-of-the-box capabilities you can make use of in the same library.

1. Creating Multi-Series Bar Charts

Apart from the single-series bar chart we built before, you can use AnyChart JS to create a multi-series bar chart that showcases multiple sets of data on the chart’s plot. In AnyChart, a series refers to a single data set that can be displayed on a chart’s plot. With a multi-series chart, you can visualize detailed information and assist your audience in deriving more insights from the data.

For example, let’s say the data is present in an HTML table (check below for the table’s code).

Here’s how the table looks on a browser:

To use the AnyChart JS library to build a multi-series bar chart out of the data, we’ll first need to include the Data Adapter module that assists in loading the HTML data into our work environment.

2. Creating Stacked Bar Charts

You can create a stacked bar chart on the fly without making extensive changes to the multi-series bar chart. AnyChart has two ways of stacking charts: value stacking and percent stacking. You can choose one of these values by setting the scale of the stackModemethod to “value” and “percent” respectively.

Here’s how to set the stackModefor a value-based JS stacked bar chart:

chart.yScale().stackMode('value');

Here’s the result:

Here’s how to set the mode for a 100% stacked bar chart:

chart.yScale().stackMode('percent');

Here’s the result:

3. Adding Interactivity to Charts

By default, JS charts created using the AnyChart library are interactive. Some of the default chart behaviors include highlighting series and points when hovered over, showing tooltips of hovered points, highlighting a series when its respective legend is hovered over, showing or hiding a series when its respective legend item is clicked on, etc.

Furthermore, you can modify the charts’ default interactivity to suit your needs and preferences. For example, we can configure the tooltip in the 100% stacked bar chart we’ve just built to give more information every time a user hovers to a point on the bar chart.